What is the disadvantage of lime soda process?

It is slow process because reactions during water softening takes place in very dilute solutions and room temp. It does not give soft water having residual hardness less than 50-60 ppm. It requires coagulant for setting particles of ppt.

What happens in lime soda process?

Lime soda process: In lime-soda process, hard water is treated with lime (CaO or Ca (OH)2) firstly, after that with soda. In this process, the hardness is removed by sedimentation as calcium carbonate or magnesium hydroxide.

What are the advantages and disadvantages of lime soda process?

Disadvantage of Lime-Soda Process:

• For efficient and economical softening, careful operation and skilled supervision in required.
• Disposal of large amounts of sludge (insoluble precipitate) poses a problem.
• This can remove hardness only up to 15 ppm, which is not good for boilers.

What is hot lime process?

If you burn Limestone (calcium carbonate) in a kiln at high enough temperatures, the water and CO2 are driven out, creating Quicklime (Calcium Oxide). Adding water to (Slaking) the Quicklime creates hydrated lime (Calcium Hydroxide). The hotlime process combines the slaking and the mortar making process together.

Which chemicals are used in lime soda process?

Chemicals normally used are lime (calcium hydroxide, Ca(OH)2) and soda ash (sodium carbonate, Na2CO3).

What is the difference between cold and hot lime soda process?

1- Hot lime soda process is carried out at high temperature (95-100°C) ,whereas cold lime soda process is carried out at room temperature (25-30°C). 2- Hot lime soda is a rapid process, but cold lime soda is slow process. 3-No coagulant is required here, in cold lime soda process coagulant is necessary.

How can CaCO3 be reduced in water?

softening through carbonate removal. When the water has a high TH accompanied by a significant M-alk., the water can be softened by using lime to remove the carbonate.

What is the function of lime and soda in lime soda process?

Chemical precipitation is one of the more common methods used to soften water. Chemicals normally used are lime (calcium hydroxide, Ca(OH)2) and soda ash (sodium carbonate, Na2CO3). Lime is used to remove chemicals that cause carbonate hardness. Soda ash is used to remove chemicals that cause non-carbonate hardness.

Why coagulants are used in lime soda method?

Alum, aluminium sulphate and sodium aluminate are used as coagulants in lime-soda process. 5. What is the function of coagulant? Explanation: Coagulants helps in the formation of coarse precipitate.

Is not needed in hot lime soda process for softening of water?

Hot Process Softening This treatment method involves the same reactions described above, except that raw water CO2 is vented and does not participate in the lime reaction. The use of lime and soda ash permits hardness reduction down to 0.5 gr/gal, or about 8 ppm, as calcium carbonate.